0
TECHNICAL PAPERS: Gas Turbines: Structures and Dynamics

Development of High-Speed Gas Bearings for High-Power Density Microdevices

[+] Author and Article Information
F. F. Ehrich, S. A. Jacobson

Gas Turbine Laboratory, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139

J. Eng. Gas Turbines Power 125(1), 141-148 (Dec 27, 2002) (8 pages) doi:10.1115/1.1498273 History: Received December 01, 2000; Revised March 01, 2001; Online December 27, 2002
Copyright © 2003 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Schematic cross section of micro-bearing rig. The rotor is 4.2 mm in diameter and 450 μm thick (0.15 μm thick blades and 300 μm long journal bearing). The rotor is centered in a rectangular die structure with dimensions 15 mm×15 mm×2.3 mm. There are two semi-circular journal pressurization plenums that can be pressurized differentially to provide side-load.
Grahic Jump Location
Schematic comparing generic types of gas thrust bearings
Grahic Jump Location
Schematic comparing generic types of gas journal bearings
Grahic Jump Location
Journal bearing etch test cross section
Grahic Jump Location
Micro-bearing rig, exploded view
Grahic Jump Location
Hydrostatic journal bearing natural frequency—macrorig (11)
Grahic Jump Location
View of the rotor plate showing the 4.2-mm diameter microturbine with 150 μm tall stator and rotor blades, two symmetric speed bumps, and four pillars for the snap-off tabs. In this picture, the journal bearing gap has not been etched or the snap-off tabs severed.
Grahic Jump Location
Operation of three microrig devices to high speed for sustained periods of time
Grahic Jump Location
Measurement of journal and thrust-balance plenum flow rates in a microrig compared to the main flow through the turbine
Grahic Jump Location
Frequency spectrum of the speed sensor signal as measured on the microrig. There is no way to distinguish whether this is indicative of a 6676 Hz or an 11,330 Hz precession frequency.
Grahic Jump Location
Frequency spectrum of the speed sensor signal from an analytic model for Ωprecessionrotation=0.37 and 0.63 (identical result for both cases)
Grahic Jump Location
Precession frequencies selected as possibly representative of the system natural frequency
Grahic Jump Location
Amplitude response curves—peak amplitude without and with penetration into the regime of hydrodynamic stiffening from a simplified perspective
Grahic Jump Location
Frequency response curve—peak amplitude with penetration into the regime of hydrodynamic stiffening in transcritical operation

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In